Method of ore separation



Patented Apr. 24, 1934 UNITEDv STATES PATENT OFFICE.

1,955,979 LIETHOD OF ORE SEPARATION Joseph P. But

Ruth Company,

No Drawing. Application August 23, 1932,

Serial No.

Colorado 3 Claims.

It is the object of thisinvention to produce an improved method for the promotion and flotation of any sulfide whose oxide,

pound of which, if precipitated on to inhibit it, is soluble that must be removed this sulfide compound or a chemical comthe surface of in a chemical prior to the addition of a promoting chemical compound and before the flotation of this particular sulfide.

The following is an example of this discovery:

iron pyrite is such as cyanide or cyanide and the zinc zinc sulfide and formed with the ore, or formed by zinc cyanide made and added to the ore in the correct quantity. If

zinc cyanide is used it efiectively inhibits both zinc sulfide and iron pyrite, but this has no the flotation of lead which easily as soon as subjected to ment in the presence of a factory promoter. After moved, the next step is purpose of removing the cyanides.

effect whatever on floats promptly and the flotation treatfrother and a satisthe lead has been reto fllter the pulp for the The ore is now repulped with fresh water, after which it is conditioned with copper. sulfate which can now treatment, thus leaving the iron the zinc sulfide froth flotation pyrite.

It has heretofore been copper sulfate to promote the cyanide was still present;

which revivifies be removed by customary to add the the zinc sulfide while this is a very difiicult operation and unless the exact amount of copper sulfate is used, the iron be promoted and floated.

Adding cyanide in pyrite will also a satisfactory quantity; in

most cases .2 pound of cyanide per ton of ore is ample to dissolve sulfide particles. While this going on, the zinc cyanide which the zinc cyanide from the zinc dissolving action is is made soluble and the straight cyanide which is present, are

in no way promoters for iron strongly tend to and at the same zinc particles. This property pyrite, in fact they further inhibit the iron pyrite time cleanse the surface of the of cyanide is easily and readily recognized as being superior to copper sulfate for this purpose.

Where cyanide is used to cleanse the zinc sulfide particles, however, it is not possible to use copper zinc without first the cyanide present in the copper sulfate used to sulting 'in a mixture that is flotation of zinc and which promotes makes it float with the zinc.

sulfate to promote the removing the cyanide because the solution interacts with promote the zinc, re-

deleterious to the the iron and In accordance with my discovery cyanide, prefasslgnor to The a corporation erably straight cyanide, is added to the ore pulp for the purpose of cleaning the zinc sulfide particles. After the ore has been subjected to a conditioning period with cyanide, it is subjected to froth flotation for the purpose of removing the lead sulfide. The ore pulp is now filtered for the purpose of removing all of the soluble cyanides and the zinc cyanide which has been formed from the interaction of the cyanide and the zinc sulfate inherently in the ore. After the pulp has been filtered, it is repulped with fresh water and conditioned with copper sulfate which now serves to promote the flotation of the zinc sulfide. suitable flotation promoter such as sodium aerofioat and a frother, such as cresylic acid, is now added and the pulp subjected to froth flotation whereupon the zinc sulfide is removed practically free from iron.

What I claim is;

1. In the flotation process for the differential separation of lead sulfide, zinc sulfide and iron sulfide, thestep of inhibiting the zinc sulfide and iron pyrite by zinc cyanide, floating to remove the lead sulfide, filtering to remove the soluble product so formed, repulping and adding copper sulfate to promote the zinc, and floating the zinc.

2. A method for the differential separation of complex sulfide ores of which an ore con lead sulfide, zinc sulfide and iron pyrite is example which comprises, adding cyanide clean the zinc sulfide particles, floating to removed the lead sulfide, filtering to remove all of the soluble cyanide and also the zinc cyanide which has been formed from the zinc sulfide, repulping the ore with fresh water, adding copper sulfate to re ,vify the zinc sulfide, adding a promoter and a frother and subjecting to froth flotation separation whereby the zinc sulfide will be floated practically free from iron.

3. In the froth flotation process for the differential separation of zinc sulfide from other sulfides, the steps of inhibiting the zinc sulfide with cyanide, subjecting to a froth flotation treatment for the removal of other sulfides that have not been inhibited, filtering to remove the cyanide JOSEPH P. RUTH, .m. 

